The PM500 is a fully programmable process meter that has two 4-20 mA sensor inputs that can be scaled to any user-selected units. The most common inputs are temperature, position, and speed. The sensor transmits the 4-20 mA signal to the PM500 via a two- or three-conductor shielded cable. The PM500 then compares this analog signal to its programmed values to determine the appropriate display value and output states. The inputs are independent of each other and can be displayed as two different processes. For example, one input could be programmed for temperature and the other for position.

With the addition of optional relay outputs and/or 4-20 mA analog outputs, the PM500 becomes a complete process control and display system. The optional relay outputs can be programmed for under-setpoint or over-setpoint operation. The 4-20 mA output can be scaled to reflect any area of the monitored range, including operations requiring an inverse output.